A fundamental requirement for any electronic device is over-current protection. Over-current is the condition where the current is greater than that rated for the device, for example due to an overload, short circuit or ground fault. As the level of current required for an over-current condition will vary according to the device, over-current protection is typically designed specifically for each device. However this can be problematic in devices which have more than one mode of operation, for example in radio devices having transceivers with different power levels.
Batteries suitable for devices such as radio communications devices typically incorporate protection mechanisms for over-current, in-rush current, and over temperature; for example in a specialised chip or integrated circuit. Thus it can be costly to modify such batteries for use with different types of devices having different over-current and other protection parameters. Similarly, such batteries may not be suitable for use with device which are capable of operating in multiple power modes; for example radio communications devices having multiple transceivers with differing power requirements.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.